From: Miklos Szeredi <mszeredi@redhat.com>
Date: Tue, 19 May 2020 14:50:37 +0200
Subject: fuse: don't check refcount after stealing page
Git-commit: 32f98877c57bee6bc27f443a96f49678a2cd6a50
Patch-mainline: v5.8-rc1
References: bsc#1206119

page_count() is unstable.  Unless there has been an RCU grace period
between when the page was removed from the page cache and now, a
speculative reference may exist from the page cache.

Reported-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Acked-by: Luis Henriques <lhenriques@suse.com>

---
 fs/fuse/dev.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index b8962581c699..ec97cabe51ce 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -764,7 +764,6 @@ static int fuse_check_page(struct page *page)
 {
 	if (page_mapcount(page) ||
 	    page->mapping != NULL ||
-	    page_count(page) != 1 ||
 	    (page->flags & PAGE_FLAGS_CHECK_AT_PREP &
 	     ~(1 << PG_locked |
 	       1 << PG_referenced |